| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <04bd63d3-e76b-4a6e-912c-6306062c91a8@intel.com>
Date: Wed, 11 Sep 2024 11:04:39 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: Changbin Du <changbin.du@...wei.com>,
Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Namhyung Kim <namhyung@...nel.org>, Nathan Chancellor <nathan@...nel.org>
Cc: Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
"Liang, Kan" <kan.liang@...ux.intel.com>,
Nick Desaulniers <ndesaulniers@...gle.com>, Bill Wendling
<morbo@...gle.com>, Justin Stitt <justinstitt@...gle.com>,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
llvm@...ts.linux.dev, Hui Wang <hw.huiwang@...wei.com>
Subject: Re: [PATCH v6 6/8] perf: build-id: extend
build_id_cache__find_debug() to find local debugging vdso
On 25/07/24 05:15, Changbin Du wrote:
> Just like vmlinux, try to search vdso in predefined paths when collecting
> build-ids. The searched paths usually have debugging info.
>
> For example, the vdso can be found in
> /lib/modules/<version>/build/arch/x86/entry/vdso/vdso*.so.dbg for local
> build on x86.
>
> Cc: Adrian Hunter <adrian.hunter@...el.com>
> Signed-off-by: Changbin Du <changbin.du@...wei.com>
>
> ---
> v3:
> - continue to try build_id_cache__find_debug_normal() if
> build_id_cache__find_debug_vdso() failed.
> v2:
> - Searching the vdso in record stage instead of report. So the debugging
> vdso will be in build-id cache. This is friendly for cross-machine
> analysis.
> ---
> tools/perf/util/build-id.c | 48 ++++++++++++++++++++++++++++++++++----
> tools/perf/util/symbol.c | 17 ++++++++++++++
> tools/perf/util/symbol.h | 1 +
> 3 files changed, 62 insertions(+), 4 deletions(-)
>
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index 5bda47de5cf2..67f88b492279 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -593,9 +593,8 @@ static int build_id_cache__add_sdt_cache(const char *sbuild_id,
> #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
> #endif
>
> -static char *build_id_cache__find_debug(const char *sbuild_id,
> - struct nsinfo *nsi,
> - const char *root_dir)
> +static char *build_id_cache__find_debug_normal(const char *sbuild_id,
"normal" is a bit vague. Perhaps just "__build_id_cache__find_debug"
> + struct nsinfo *nsi, const char *root_dir)
> {
> const char *dirname = "/usr/lib/debug/.build-id/";
> char *realname = NULL;
> @@ -646,6 +645,47 @@ static char *build_id_cache__find_debug(const char *sbuild_id,
> return realname;
> }
>
> +static char *build_id_cache__find_debug_vdso(const char *sbuild_id)
> +{
> + char sbuild_id_tmp[SBUILD_ID_SIZE];
> + struct build_id bid;
> + int i, ret = 0;
> +
> + if (!vdso_paths.paths)
> + return NULL;
> +
> + pr_debug("Looking at the vdso_path (%d entries long)\n",
> + vdso_paths.nr_entries + 1);
> +
> + for (i = 0; i < vdso_paths.nr_entries; ++i) {
> + ret = filename__read_build_id(vdso_paths.paths[i], &bid);
> + if (ret < 0)
> + continue;
> +
> + build_id__sprintf(&bid, sbuild_id_tmp);
> + if (!strcmp(sbuild_id, sbuild_id_tmp)) {
> + pr_debug("Found debugging vdso %s\n", vdso_paths.paths[i]);
> + return strdup(vdso_paths.paths[i]);
> + }
> + }
Doesn't cover symfs or mount namespace like the other one does.
> +
> + return NULL;
> +}
> +
> +static char *build_id_cache__find_debug(const char *sbuild_id,
> + struct nsinfo *nsi,
> + bool is_vdso,
> + const char *root_dir)
> +{
> + char *name = NULL;
> +
> + if (is_vdso)
> + name = build_id_cache__find_debug_vdso(sbuild_id);
> + if (!name)
> + name = build_id_cache__find_debug_normal(sbuild_id, nsi, root_dir);
> + return name;
> +}
> +
> int
> build_id_cache__add(const char *sbuild_id, const char *name, const char *realname,
> struct nsinfo *nsi, bool is_kallsyms, bool is_vdso,
> @@ -702,7 +742,7 @@ build_id_cache__add(const char *sbuild_id, const char *name, const char *realnam
> * symtab.
> */
> if (!is_kallsyms && strncmp(".ko", name + strlen(name) - 3, 3)) {
> - debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir);
> + debugfile = build_id_cache__find_debug(sbuild_id, nsi, is_vdso, root_dir);
> if (debugfile) {
> zfree(&filename);
> if (asprintf(&filename, "%s/%s", dir_name,
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 6bf75c98e1f2..8e982e68b717 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -49,6 +49,7 @@ static int dso__load_vdso_sym(struct dso *dso, struct map *map);
> static bool symbol__is_idle(const char *name);
>
> struct dso_filename_paths vmlinux_paths;
> +struct dso_filename_paths vdso_paths;
>
> struct symbol_conf symbol_conf = {
> .nanosecs = false,
> @@ -2303,6 +2304,16 @@ struct dso_filename_pattern vmlinux_patterns[] = {
> {"/usr/lib/debug/boot/vmlinux-%s.debug", 1},
> };
>
> +struct dso_filename_pattern vdso_patterns[] = {
> + {"/lib/modules/%s/vdso/vdso.so", 1},
> + {"/lib/modules/%s/vdso/vdso64.so", 1},
> + {"/lib/modules/%s/vdso/vdso32.so", 1},
> + {"/lib/modules/%s/build/arch/%s/vdso/vdso.so.dbg", 2},
> + {"/lib/modules/%s/build/arch/%s/kernel/vdso/vdso.so.dbg", 2},
> + {"/lib/modules/%s/build/arch/%s/entry/vdso/vdso32.so.dbg", 2},
> + {"/lib/modules/%s/build/arch/%s/entry/vdso/vdso64.so.dbg", 2},
> +};
> +
> static int dso_filename_path__add(struct dso_filename_paths *paths, const char *new_entry)
> {
> paths->paths[paths->nr_entries] = strdup(new_entry);
> @@ -2565,6 +2576,11 @@ int symbol__init(struct perf_env *env)
> return -1;
> }
>
> + if (dso_filename_path__init(&vdso_paths, vdso_patterns,
> + ARRAY_SIZE(vdso_patterns), env) < 0) {
> + return -1;
> + }
> +
> if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
> pr_err("'.' is the only non valid --field-separator argument\n");
> return -1;
> @@ -2641,6 +2657,7 @@ void symbol__exit(void)
> intlist__delete(symbol_conf.pid_list);
> intlist__delete(symbol_conf.addr_list);
> dso_filename_path__exit(&vmlinux_paths);
> + dso_filename_path__exit(&vdso_paths);
> symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
> symbol_conf.bt_stop_list = NULL;
> symbol_conf.initialized = false;
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index 30056884945b..08c339594d4e 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -107,6 +107,7 @@ struct dso_filename_paths {
> };
>
> extern struct dso_filename_paths vmlinux_paths;
> +extern struct dso_filename_paths vdso_paths;
>
> static inline void *symbol__priv(struct symbol *sym)
> {
Powered by blists - more mailing lists